What is the difference between fractional abundance and natural abundance?
What is the difference between fractional abundance and natural abundance?
In physics, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass of these isotopes is the atomic weight listed for the element in the periodic table.
The abundance of an isotope varies from planet to planet, and even from place to place on the Earth, but remains relatively constant in time (on a short-term scale).
As an example, uranium has three naturally occurring isotopes: 238U, 235U and 234U. Their respective natural mole-fraction abundances are 99.2739–99.2752%, 0.7198–0.7202%, and 0.0050–0.0059%.
Abundance shown as a fraction is called fractional abundance. Natural abundance is shown as percentage, but fractional abundance is shown as fraction, a number from 0 to 1. Also, fractional abundance is a single value , and not a range , but natural abundance is usually a range of values.
Also, natural abundance shows abundance of isotopes in a planet. But fractional abundance can show abundance of isotopes in a system, or a planet, or an expeimental system. Generally, unless specified, fractional abundance is a just natural abundance shown as fraction.
Example- uranium has three naturally occurring isotopes: 238U, 235U and 234U. Their respective fractional mole-fraction abundances are 0.9927, 0.00719, and 0.00011 respectively.
In physics, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass of these isotopes is the atomic weight listed for the element in the periodic table.
The abundance of an isotope varies from planet to planet, and even from place to place on the Earth, but remains relatively constant in time (on a short-term scale).
As an example, uranium has three naturally occurring isotopes: 238U, 235U and 234U. Their respective natural mole-fraction abundances are 99.2739–99.2752%, 0.7198–0.7202%, and 0.0050–0.0059%.
Abundance shown as a fraction is called fractional abundance. Natural abundance is shown as percentage, but fractional abundance is shown as fraction, a number from 0 to 1. Also, fractional abundance is a single value , and not a range , but natural abundance is usually a range of values.
Also, natural abundance shows abundance of isotopes in a planet. But fractional abundance can show abundance of isotopes in a system, or a planet, or an expeimental system. Generally, unless specified, fractional abundance is a just natural abundance shown as fraction.
Example- uranium has three naturally occurring isotopes: 238U, 235U and 234U. Their respective fractional mole-fraction abundances are 0.9927, 0.00719, and 0.00011 respectively.
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